Means for protecting boilers, pipes, &amp;c., from corrosion.



No. 629,092. Patented July l8, I899. H. S. ROSS. HEANS FOR PROTECTINGBOILERS, PIPES, 8113., FROM CORROSION.

(Application filed Jan. 25, 1898.)

(No Model.)

WI TNESS Br ykq fl a ATTORNEY NrrEn Sterne l arsw'r Fries.

MEANS FOR PROTECTlNG BOILERS, PIPES, &c., FROM CORROSION.

SPECIFICATION forming part of Letters Patent No. 629,092, dated July 18,1899. Application filed January 25. 1898. Serial No. 667,876. No model.

To (LZZ whom it may concern:

Be it known that I, HENRY Scnu YLER Ross, a citizen of the UnitedStates, and a resident of the city, county, and State of New York, haveinvented certain new and useful Improvements in Means for ProtectingBoilers, Pipes, &c., from Corrosion, of which the following is aspecification.

The object of my invention is to provide a simple, effective, andeasily-applied means for protecting the interior walls of boilers,pipes, and other vessels from corrosion. It has long been known thatsuch corrosion can be prevented by placing on the interior of saidvessels pieces of zinc or other metal of a nature to corrode more easilythan the metal to be protected and establishing, close metal contactbetween them. Many ditiiculties have attended the commercial applicationof this well-known fact, among which may be mentioned the necessity forblowing elf the boiler or otherwise emptying the vessel when thecorroded zinc has to be replaced, the short time during which theprotection is effective, and the uncertainty of action of the variousdevices employed. My invention overcomes these dil'liculties and others;and it consists of a plug of brass or other comparatively non-corrodingmetal and provided with a tip of zinc or other more easily cor rodedmetal interlocking with the body of said plug by a joint which isthoroughly protected or sealed by a gromet or otherwise from the attackof the corrosive substance in which said zinc tip is submerged, saidcomposite plug being adapted to be inserted through the wall of aboiler, pipe, or other 'vessel in such manner as to resist the pressurecreated therein.

In the accompanying drawings, Figure 1 shows my composite plug arrangedwith the zinc tip screwing into the brass plug. Fig. 2 shows the plug soarranged that the zinc tip surrounds the interlocking parts of the brassplug.

The same letters indicate similar parts in the difierent figures.

A is a fragment of the wall of a boiler, pipe, or other vessel theinterior of which is to be protected from corrosion.

13 is the body of the plug, which maybe made of brass or othercomparatively noncorroding metal.

Z is the zinc tip.

\Vhen used in the form shown in Fig. 1, the plug is formed with anexternal screwthread I), which engages with a thread cut in the openingthrough the wall A.

\Vhen the plug is made in the form shown in Fig. 2, the body of the plugconsists of a piece of piping P, which has the same externalscrew-thread b for the same purpose, and the brass piece B passesthrough said piping into the tip Z. Where the tip screws into the bodyof the plug, a simple screw-thread 2, external on the reduced end of thetip and internal on the plug, is sufficient. When, on the other hand,the plug screws into the tip, it is desirable to have the threads 2 2,(shown .in Fig. 2,) by means of which the two parts can be drawntogether by turning the brass plug B.

G is a gromet or gasket of rubber or other impervious material, whichserves to protect not only the joint made between the zinc tip and thebrass plug, but also the joint between the plug and the metallic wall ofthe vessel. These plugs are to be inserted through the wall of thevessel below the water-line and at such intervals as may be necessaryfor the thorough protection of the interior. Each plug byeorrodingprotects the surrounding wall for a radius which varies with the exposedsurface of the plug. It is better, however, to have smaller plugs atshorter intervals than larger plugs at larger intervals. A plugone inchin diameter, with an effective protecting radius of about two feet,makes a convenient size and can be of course used at intervals of everyfour feet.

, The protection of the joints from attack by the corrosive liquidswhich may be present in the interior of the vessel is of very greatimportance, as will be readily understood when the action which takesplace is analyzed.

A current of a voltaic character'is established through a circuit ofwhich the metals of the plug and vessel, with their interlocking jointsand a portion of the corrosive liquid, form parts. This current,however, is very gentle, and the creation of even a slight resistance inthe circuit practically acts as a break in the circuit, causing thecurrent to cease flowing. This resistance is created by even a slightamount of oxidation at any of the joints, and this oxidation is sure totake place if the corrosive fluids have access to the joints made by thedissimilar metals. A gasket or ring of cement or other non-corrodingmaterial, which extends over all of these joints wherever they wouldotherwise be subject to contact with the corrosive liquid, I have foundto be an efiective Way of securing protection of the joints.

I claim The above-described means for protecting boilers, pipes, rise.from corrosion, which consists of a plug of comparatively non-corrodingmetal provided with means for securing it in electrical contact with theboiler or other vessel a tip of more easily corrodible metal securedthereto and in metallic contact therewith, aud means, covering the jointbetween the plug and the tip, for-protecting said joint 25 againstcorrosion.

HENRY SCIIUYLER ROSS. Witnesses:

W. P. PREBLE, J r., J. KENNEDY.

